Recent experimental evidences have demonstrated that expression of the vanilloid TRPV1 receptor (transient receptor potential channel) increases in inflammatory conditions. This led to hypothesize that TRPV1 antagonists could be useful for the treatment of inflammatory processes, for example chronic pain and inflammatory hyperalgesia.
A number of antagonists of the vanilloid receptor are known; some of them derive from capsaicin and are called capsaicinoid antagonists. In particular, Wrigglesworth, R. et al (J. Med. Chem. 1996, 39, 4941-4951) disclosed the thiourea of formula (II):
